FIG. 9 is a constitutional view showing one example of a conventional haptic feedback controller (see patent document 1, for example). FIG. 9A is a perspective view showing appearance of the haptic feedback controller 500, and FIG. 9B is an exploded perspective view of the haptic feedback controller 500. Further, FIG. 10 is a block diagram for explaining functions of the conventional haptic feedback controller 500.
The haptic feedback controller 500 includes, as shown in FIG. 9, a base 510, a cap 520 and a piezoelectric motor 530.
The base 510 has a ring shape, and the cap 520 has a ring shape in the same manner as the base 510 and is mounted on the base 510 in a rotatable manner relative to the base 510.
The piezoelectric motor 530 is, as shown in FIG. 9B, arranged between the base 510 and the cap 520. The piezoelectric motor 530 includes a ring-shaped stator 540 and a ring-shaped rotor 550.
The haptic feedback controller 500 having such constitutional elements further includes, as shown in FIG. 10, a rotation control device 610 which controls a rotational state of the piezoelectric motor 530, a rotational state detection device 620 which detects a rotational state of a cap 520 relative to the base 510, an input/output device 630 which has a function of outputting rotational state information based on a detection result of the rotational state detection device 620 to, for example, a personal computer (hereinafter referred to as PC) 700 which constitutes controlled equipment and a function of receiving feedback information for controlling a piezoelectric motor outputted from the PC 700, and a control part 640 which performs a control of the rotational control device 610, the rotational state detection device 620 and the input/output device 630.
The haptic feedback controller 500 can be used in the following manner.
A user, first of all, rotates the cap 520. Then, the rotational state detection device 620 detects a rotational state of the cap 520 relative to the base 510, and outputs a detection result to the control part 640. The control part 640 outputs rotational state information based on the detection result of the rotational state detection device 620 to the PC 700 via the input/output device 630 so that the PC 700 performs a necessary control.
Here, the PC 700 outputs, based on the rotational state information and a state of an application operated in the PC, feedback information used for controlling a rotational state of the piezoelectric motor 530 to the haptic feedback controller 500. The input/output device 630 receives inputting of feedback information from the PC 700 and, at the same time, outputs the feedback information to the control part 640. The control part 640 outputs the feedback information to the rotation control device 610 thus performing a rotational control of the piezoelectric motor 530.
In such a haptic feedback controller 500 having such a constitution, when a user operates the cap 520, haptic feedback is imparted to the piezoelectric motor 530 and, eventually, to the cap 520 in response to such an operation.
Further, the piezoelectric motor 530 which the haptic feedback controller 500 includes exhibits excellent response characteristic, can change over the rotational direction at a high speed, and exhibits high resolution in operation along the rotational direction. Accordingly, the user can easily acquire simple-to-control and gentle haptic feedback and hence, the user can operate the cap 520 smartly or skillfully thus allowing the haptic feedback controller 500 to possess versatile expressive powers on haptic feedback.    Patent document 1: International Publication WO2006/051581.